I'm starting to mod/rebuild my boat and am rewiring all the electronics.  I'll get around to posting some pictures as the build gets going a little later.  To say the least, I'm not going to follow the previous owner's wiring method which has become a pile of rusty alligator clips.  Here are a few of my ideas.

3 batteries, two are identical.   12v 36 lb (?)  trolling motor

setup 1

battery 1 - cranking and bilge

battery 2 - 2 fishfinders, running lights, live well, horn

battery 3 - trolling motor

setup 2

battery 1 - cranking and everything else

batteries 2 and 3 - trolling motor

If I'm not making long runs will running all my accessories off the cranking battery kill it after a full day of fishing?  How big of a circuit breaker do I need for the trolling motor?  It's an evinrude and I can't find any amp or voltage numbers on it.

Thanks

What is your TM voltage? If 12v hook 2 batteries in parallel. If 24v hook 2 batteries in series. I suspect 2 batteries are deep cycle and 1 is cranking. The deep cycles are for the TM and the cranking for the big motor and every thing else which is how my boat and most others are wired. I have no problems with this setup.

Thanks NBR, the trolling motor is 12v

Are batteries 2 and 3 connected together or is battery 2 with the electronics, livewell, lights and horn just a back-up for the trolling motor battery 3?

Are batteries 2 and 3 connected together or is battery 2 with the electronics, livewell, lights and horn just a back-up for the trolling motor battery 3?

The two identical batteries that I have would be connected in parrallel to run the trolling motor.  Fishfinders, bilge and livewell pumps, running lights, would be run off the cranking battery.  

I hadn't considered the backup idea and finding out that one of my fishfinders is dead (old cheap fish eagle that came with the boat), I wouldn't be running much extra off the cranking battery.

Keep the trolling motor on seperate batteries. Everything else will be fine on the other as long as you keep the charge up.

My boat is setup

1. Cranking battery - Bilge, Depth Finders, etc

2. Deep Cycle- trolling motor

3. Deep Cycle- trolling motor

2 and 3 are hooked in parallel to a 12 volt trolling motor to give me longer run times between charges. i have never had good luck hooking a depth finder to a tm battery. They need a more steady 12 volts that a cranker can provide.

Harshman

my 2 cents